Plaster over fresh plaster

[Eddm87]

Hi all, just a quickie

trying my hand at plastering, starting with a small utility room, all pb, then I’m 1coat skimming it.
3 walls went well, with a touch of easifill in some patches.

The last wall I have now redone twice as I wasn’t happy with it.
It seems different to me though, it’s like the plaster is going off way too early.
Do I need to pva the wall first?

Also, roughly how long do I need to wait for the first troweling? Seems I’m always chasing my tail!

thanks
Edd

 

[lostinthelight]

Too many variable to put a time on it I would say , I think you may be making more difficult for yourself by trying to do it in one coat. If your trying to correct prevous attempts and left it you'll have to stop it sucking one way or another and pva seems a good choice.
Its not a good time of year for learners, I count myself in that group, especially if youve got the mix a bit stiff and your not getting on the wall fast enough.

 

[perky416]

Make sure youre not over mixing the plaster. I found this recently. I was spending 5 or 10 mins mixing a batch with a mixer in my drill, adding a bit of plaster...bit of water...bit of plaster etc.
Now i do it all in one go using a proper paddle mixer and it is so much better. I also make it a little on the wetter side.

I do one coat...flatten it straight away.
Then 2nd coat...flatten it straight away.
Let it go off a bit so it is just tacky.
Sponge float it. Flatten again if needed.
Sponge float. Go over with my finishing trowel.
Final trowel off as its going off.

 

[Eddm87]

Thanks for reply’s.
Pva’d it with a 1:4 mix, then with a 1:3 mix. Went on like a dream.
Thanks perky, got a proper paddle mixer after I mucked it up the first couple of times!
Here’s a novice question though… why 2 coat it? My process is to get a skim coat on, flatten it once, wait 10 mins, second trowel it, 10mins, third trowel, then 10 mins, spray with water mist and final trowel it.
I know your ‘supposed to’ two coat it but how/why would you?

edd

 

[lostinthelight]

I expect you've read this type of thing to death?
https://www.diyplastering.co.uk/2nd-coat-of-plaster.html